Analysis On Characteristics And Study On Control Strategy Of Giant Magnetostrictive Actuator

Giant magnetostrictive actuators, characterized by high force, large displacement, fast response, high resolution and so on, have a broad application prospect in microdisplacement actuator, robotics, active vibration control and so on. However, output characteristic of giant magnetostrictive actuators exhibits hysteresis nonlinearity, which presents a challenge in the applications and development.In this dissertation, a nonlinear dynamic model of giant magnetostrictive actuators is analysed, which based on J-A hysteresis model, piezomagnetic equation, quadratic moment domain rotation model and the dynamics characteristics. And numerical realization method, which is for the nonlinear dynamic model established, is studied.In order to improve the positioning accurary of controlling system for giant magnetostrictive actuator, compound control strategy is presented through the combination of fuzzy and PID.Fuzzy integral effect is introduced into the traditional fuzzy controller to achieve a Fuzzy-PID control; the different control mode is applied to the various phases in the controlling process.P-Fuzzy PID controller is designed with MATLAB fuzzy logic toolbox.Under simulink environment, control experiment is done based on P-Fuzzy PID control ,traditional fuzzy control and conventional PID control. Through the comparison and analysis, it is found that P-Fuzzy PID maintain the advantages of the traditional fuzzy control,and improve its response speed and sensitivity.P-Fuzzy PID control is better than conventional PID control,and the P-Fuzzy PID controller enables the system to be of good fastness, no-overshoot and very high accuracy.Eventually, a P-Fuzzy PID with inverse compensation is proposed, and the software realizing methord of inverse model compensation with BP neural network in the feed-forward loop and P-Fuzzy PID control in the closed loop is investigated.